Posted
by
kdawson
on Sunday March 29, 2009 @04:23AM
from the lives-of-a-virus dept.

Technology Review has promising news on the AIDS front: researchers have captured HIV T cell transmission on video. The upshot could be new avenues of treatment. "The resulting images and videos show that, once an infected cell adheres to a healthy cell, the HIV proteins... migrate within minutes to the contact site. At that point, large packets of virus are simultaneously released by the infected cell and internalized by the recipient cell. This efficient mode of transfer is a distinct pathway from the cell-free infection that has been the focus of most prior HIV studies, and reveals another mechanism by which the virus evades immune responses that can neutralize free virus particles within the body."

> Roxx, on learning about James being HIV-positive, said, "It totally made me realize how I trusted this system that wasn't to be trusted at all, because it obviously doesn't work," and "I thought porn people were the cleanest people in the world."

"The system" in this case is inherently flawed.

After initial HIV infection, it can take up to six months for someone to start producing HIV antibodies (seroconvert). And unfortunately, most HIV tests don't check for viral load, but check for the presence of antibodies.

So basically, you have a window period of up to six months where you are contagious but will come up negative on tests.

I think the interesting part about this discovery is that aids is traveling from cell to cell without the need to release virons to float around hoping to find a cell. I don't recall hearing about any other virus that spreads by cell-to-cell contact. It appears as though the infected cell press up against an uninfected cell, form a pocket between them (that is not connected to "outside" and then release some virons into this pocket. The virons contain the necessary "key" to get into a cell, but normally their odds are not good simply because they have to float around and hope to bump into a T cell, one at a time, in just the right way.

This process has several advantages. First, it's not wasting virons by simply multiplying them inside the cell until the cell bursts, leaving the virons to float around hoping for a chance contact. Second, since the body isn't being flooded with virons, it severely delays and slows the auto immune response of the body which isn't going to react anywhere near as fast to such a low-volume threat of a handful of virons leaking out now and then vs thousands popping onto the scene continually. Third, in addition to being hand-delivered to a target cell, there's a ton of them at the contact site concentrated right on the target cell's doorstep, not just one, so infection is pretty much guaranteed.

It's sort of the difference between a country sending an "army" to their enemy, by stirring up a villagefull of people to go attack on their own individually, vs assembling a strike force and attacking at one spot on the wall all at once. Clearly the latter is more effective.

Scarry stuff. AIDS looks to have evolved a very potent new method of infection. It's too bad we don't know more about how this process works. AIDS is probably throttling its viron production so the infected cell survives to infect other cells, rather than multiplying virons as fast as possible to get the most of them released into the body as fast as possible. Interferfon iirc slows the replication of AIDS virons inside the cell, so it makes sense that throttling an already throttled process should be an effective treatment.

If a cell has been taken over and is personally going to another cell and staging an attack, this may be a very difficult problem to overcome. Small, relatively inert virons can only hope for a chance contact in just the right way with a target cell. An entire cell coming to get you is a bit more like a bacteria problem, they have a heck of a lot more resources at their disposal. It's like the enemy taking over one of your tanks, vs coming at you as a walking soldier. Difference is, when the enemy "gets you", he doesn't destroy your tank... he dumps some men INTO your tank and now he has TWO tanks.

What this all boils down to is AIDS has found a new way to use the cells it hijacks. Most other viruses use them as self-destructing viron factories, and a few as places to hide and lay dormant for later relapse. But using cells as lingering attack platforms is just plain scarry.

Random musing: Perhaps the regulatory mechanism for virus reproduction in the cell can be attacked. Find a way to convince the infected cell that it is already packed with new virons. It wouldn't be a cure, but might be a decent long term treatment with less side effects.

Ah, the old "you first" defense; The shield of the coward. That's okay. I'll play along.

The person that I replied to [slashdot.org] was mixing up the usage of HIV and AIDS. Every time he said AIDS, he should have said HIV for his sentences to make sense. People often use the terms interchangeably but they are different things. HIV is a virus and it's that virus that infects people. AIDS is a syndrome that HIV infected people can, and usually do, develop sometime after infection. AIDS isn't transmissible any more

Interferon iirc slows the replication of AIDS virons inside the cell, so it makes sense that throttling an already throttled process should be an effective treatment.

...

What this all boils down to is AIDS has found a new way to use the cells it hijacks. Most other viruses use them as self-destructing viron factories, and a few as places to hide and lay dormant for later relapse. But using cells as lingering attack platforms is just plain scary.

Wait, so why does interferon seem like a good treatment? From what you say it would perhaps delay progression of the virus's spread, but not fundamentally disrupt its operation.

OTOH, perhaps going the other way would have merit. If the virus is so clever because its viron strategy is both stealthy and targeted, perhaps it's worth researching a way to speed up viron production. Then there would be greater chance of early immune response, and of premature death of infected cells. Right?

Wait, so why does interferon seem like a good treatment? From what you say it would perhaps delay progression of the virus's spread, but not fundamentally disrupt its operation.

My musing here is that maybe it's worked out that it's more effective to spread directly by cell-to-cell over the long term than to dump out a ton of virons and explode the cell.

Now the immune system is capable of identifying infected cells, but that's a lot harder to identify than a viron. So that is probably working to its advantage also. The white blood cells probably also have an easier time identifying a cel that's not doing its job anymore and is swollen with virons

Well, so, again, why isn't it a better research goal to force the virus to speed up viron production (thus defeating the cleverness you highlight), rather than helping it to slow down viron production (which enhances the cleverness you highlight)?

Well, so, again, why isn't it a better research goal to force the virus to speed up viron production (thus defeating the cleverness you highlight), rather than helping it to slow down viron production (which enhances the cleverness you highlight)?

The reason this is bad:

First, quick background:

HIV is a retro virus. It reverse engineers its RNA into DNA and the DNA incorporates into the nucleic region. The viral DNA normally will lie dormant through a few mitosis cycles. At some point, an unknown chemica

pretty much anything that can cause cell-to-cell fusion at a neutral pH can do this.http://www.nature.com/nrmicro/journal/v6/n11/abs/nrmicro1972.html [nature.com]
The initial stages of animal virus infection are generally described as the binding of free virions to permissive target cells followed by entry and replication. Although this route of infection is undoubtedly important, many viruses that are pathogenic for humans, including HIV-1, herpes simplex virus and measles, can also move between cells without diffus

You're currently modded at -1, but upon reading your reply I wondered if you were actually infected and demonstrating a remarkable sense of humor about it. I say that as someone who knows a really remarkable human being (a linguistics guy who speaks and tutors in seven languages) who has been infected for 16 years, and by some miracle is still alive. If you're not infected, that was a pretty bad joke. If you are actually infected, you've earned some respect for being strong enough to be witty about it.

I disagree. The humor of "I'm *, you insenstitive clod!" is fairly transparant: it isn't about animus it is about insensitivity (and clodishness).

I try not to make fun of people who suffer from some bizarre and cruel disadvantage because I don't know what it is like to, say, have my family mauled by amok giraffes. If I make a joke about that unfortunate circumstance and someone says "My family was mauled by amok giraffes, you insensitive clod!" the humor is 1) that there is no misfortune so unlikely that

You're currently modded at -1, but upon reading your reply I wondered if you were actually infected and demonstrating a remarkable sense of humor about it. I say that as someone who knows a really remarkable human being (a linguistics guy who speaks and tutors in seven languages) who has been infected for 16 years, and by some miracle is still alive. If you're not infected, that was a pretty bad joke. If you are actually infected, you've earned some respect for be

I'm certain my wife will be most distressed to learn of this most unfortunate development in my health. Thank you for this critical update on my health.

In all seriousness, it's really not funny to joke about this sort of thing. Do you enjoy joking about cancer patients? How about young women who contract cervical cancer via HPV from their partners? Real funny, buddy.

Patients on the chemotherepy ward were discussing how Cervical Cancer is more prevalent in women who start having sex early, have sex often and/or with multiple partners.

The conclusion they came to is that excess stimulation of a sexual nature actually causes the cancer to develop. The guy with testicular cancer nodded approval, the woman with Brest cancer started to cry, The woman with throat cancer managed to cough out "not true".

The guy with Prostate Cancer ran away screaming "I am not gay. I am not gay"

Yes, as long as it's funny. Just like Forge's post in response to the same post I'm responding to. I enjoyed Forge's joke quite a bit.:)

This isn't me singling out cancer patients, by the way. I enjoy any joke that's funny, regardless of group. Whites, Catholics, nerds, college students, socially inept people who hang out on the Internet...I'm a part of each of those groups, and I can laugh at jokes. And all the same, I can also laugh at jokes about blacks, Jews, jocks, or any number of groups of which

I'm certain my wife will be most distressed to learn of this most unfortunate development in my health. Thank you for this critical update on my health.

In all seriousness, it's really not funny to joke about this sort of thing. Do you enjoy joking about cancer patients? How about young women who contract cervical cancer via HPV from their partners? Real funny, buddy.

There is nothing, absolutely nothing, that cannot be turned into a topic of humour. Humans do it with war, with disease, with famine, with

Sigh... it's not really a matter of taboo for me, just my own views on decency. I'm not advocating censorship of any kind here, mind you, just voicing my opinion. I've got a fairly warped sense of humor, too... the Navy tends to do that to people:). Still, there are some things I just can't bring myself to joke about, mostly due to direct personal experience in those matters.

American Society for Microbiology (2008, June 5). Humans Have Ten Times More Bacteria Than Human Cells: How Do Microbial Communities Affect Human Health?. ScienceDaily. Retrieved March 29, 2009, from http://www.sciencedaily.com&#194;&#173;/releases/2008/06/080603085914.htm

I have an idea how to stop HIV and it involves the same technology found in terminator seeds [wikipedia.org].

In a nutshell, the government sanctions the agricultural giant Monsanto to engineer a new strain of HIV virus with a limited lifespan beyond a certain generation with ability to recode the DNA as it progresses. This virus could be hostile to all the known HIV strains out in the wild and force them out. People voluntarily get infected with this new virus as means of guarding against incurable HIV infections. Since this new virus can be regulated upon demand, Monsanto can then minimize the damage for a low monthly fee by supplying you with various off switches to reduce the infection. They could set up various plans depending on your budget. Silver and Gold plans would have limited side effects to encourage you to upgrade to the Platinum plan and get better viral sterilization methods.

the government sanctions the agricultural giant Monsanto to engineer a new strain of HIV virus with a limited lifespan beyond a certain generation with ability to recode the DNA as it progresses

Is that even feasible? I'm not a virologist, but adding a feature like this seems pretty complicated. Is there an easy way to do that, like adding one gene from another virus, or are you proposing we invent a whole new mechanism from scratch? Because we're really no good at that yet. Pretty much all the artificial genes that I'm familiar with are either genes we've copied from natural ones, or ones that are extremely rudimentary compared to natural ones.

I'm not a virologist either, but I have taken classes in the subject (some time ago, so don't take what I say as doctrine or anything). The idea of a competing virus does have some merit. IIRC, research was done on the topic with ex vivo models, but I don't think it ever made its way to animal subject or human trials.

For this to work, you'd ideally want a virus which used the same antigen for cellular entry (gp120, CD40 ligand); this keeps your virus to the same cells that are susceptible to HIV, limiting

this blurb reads like researcher have been ignoring cell-to-cell contamination for the last 20 years and only tried to get a cure for "free virus" to cell contamination. I hope it's not what actually happened that would be sad. Nice video though.

The blurb does kind of make it sound that way, the third sentence in the actual science article cites a 1993 paper: "In vitro, infection with cell-associated HIV can be thousands fold more efficient than infection with cell-free virus."

Protein dynamics can be affected by alterations to the protein itself. In this case, the gag protein had GFP inserted into it. GFP itself dimerizes weakly, and would add some size and weight to the protein. Does anyone know how they are sure what they're seeing matches normal Gag dynamics? The paper says "This virus faithfully reveals Gag localization, allowing infected cells and viral particles to be tracked with high sensitivity" citing an earlier paper by the same authors. That paper showed that it

sqlite is public domain. If the authors don't care that Real Basic uses it, why do you?

Also [wikipedia.org], 48% of HIV cases (in the US as of 2003) were tracked to male-on-male gay sex. 47% of the US HIV-positive population is black. Any mention of that seems to result in a -1 moderation.

The "funny" thing about HIV is that, if it killed instantly (days or weeks) people would be MUCH more apt to be careful and NOT GET IT it because it's completely preventable aside from rape, unknowingly getting it through blood transfusions (rare) etc.

The "funny" thing about HIV is that, if it killed instantly (days or weeks) people would be MUCH more apt to be careful and NOT GET IT it because it's completely preventable aside from rape, unknowingly getting it through blood transfusions (rare) etc.

If it killed within days or weeks, it wouldn't matter what people do, because an outbreak would be pretty much self-terminating.

HIV causing AIDS? It's a consensus that has an overwhelming amount of evidence to back it up. I won't even begin to try to summarize it all, but I will describe the gist of it.

Causality between a microorganism and disease is commonly established through the demonstration of Koch's Postulates [wikipedia.org]. These are not hard-fast rules; some of Koch's Postulates are difficult to prove through ethical experiments. However, in the case of HIV, all of Koch's Postulates have been fulfilled:

The microorganism must be found in abundance in all organisms suffering from the disease. The virus has been isolated from every patient with AIDS. On top of that, people have sequenced its genome, elucidated its structure, and taken a picture of it.

The microorganism must be isolated from a diseased organism and grown in pure culture. The virus has been isolated from patients with AIDS, and grown in culture. Critics cite the fact that this is very difficult to do, and requires special conditions. Most scientists believe that such special conditions are necessary when you are trying to culture something like a retrovirus. Special requirements for growth are not unique to HIV; for example, no one has ever successfully cultured a pathogenic strain of Treponema pallidum (syphilis) in vitro, but anyone who has ever had syphilis will tell you it is a VERY real disease.

The cultured microorganism should cause disease when introduced into a healthy organism. When introduced into a healthy individual, the HIV virus has been found to cause disease. It should be noted that this has only happened a few times in monitored environments, through needle-stick exposures; however, it would not be ethical to experimentally inoculate a healthy person with HIV. There is an overwhelming body of non-experimental evidence to support bloodborne and sexual transmission of the HIV virus, and the evidence shows that everyone who contracts HIV eventually gets AIDS - with OR without therapy.

The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent. This has been demonstrated in the cases of needle-stick exposures.

Anti-retroviral therapy - while itself is quite dangerous and filled with side effects - has nevertheless been shown in numerous studies to reduce morbidity and mortality in HIV+ patients. Anti-retroviral therapy has also been compared to placebo, and its effects have been found to be beneficial over placebo. Other studies, mostly performed in Africa, have examined the "natural history" (i.e. the untreated progression) of HIV infection; such studies have shown that the natural history of HIV infection leads to the severe immunocompromise characteristic of the AIDS syndrome, followed by death.

Yes, there is plenty of money flowing into AIDS research and drugs. However, that fact fails to prove anything related to this discussion, one way or another. There was a point in time when the HIV-AIDS connection was, indeed, a hypothesis; many people cite evidence from that period of time in making the claim that HIV->AIDS is still a widely disputed theory. However, a careful examination of the current scientific evidence will reveal an overwhelming body of evidence supporting a causal relationship between HIV and AIDS.

Shouldn't (1) include something like "and never found in abundance in organisms not suffering from the disease"
? I realize that (3) is attempting something like that but it isn't quite the same. Although it would be better if (3) said "always found to cause the disease" or something similar.

Causality is different from virulence. You do not need modifiers like "always" or "never" to establish causality. A microorganism can cause disease in some individuals and not in others; it can cause disease sometimes, and other times not. This (somewhat frustrating) aspect of infectious disease results from the complexity of the interplay between the microbe, your body, your body's immune system, and the environment.

For example, you can have Hepatitis B virus floating around in your blood, but have n

Shouldn't (1) include something like "and never found in abundance in organisms not suffering from the disease"

Absolutely not.

It's always possible, and in fact quite likely, that there will be portions of the population who can carry the infection without developing symptoms. Carriers of HIV+ who do not develop symptoms of AIDS are not unheard of, but then again carriers of flu viruses who do not develop the flu are fairly common.

The problem is how the industry defines AIDS. It is defined as having immune deficiency and HIV (except in Africa, where a whole host of diseases are called "AIDS" due to lack of HIV testing). It begs the question, and invalidates postultes 1 and 4. #3 is mostly based on, as you put it, non-experimental evidence, which isn't bad in itself except there aren't any statistical controls, either, making it unscientific as well.

You are right that the formal definition of AIDS leads to circular logic (HIV causes AIDS, AIDS is defined by HIV). The fact remains, however, that the evidence shows that HIV leads to a syndrome of severe immunocompromise - we can call it AIDS, or we can call it severe HIV-associated immunocompromise, but whatever we call it, it's something and it's real and the evidence would strongly suggest that it is caused by HIV. Such "invalidation" of postulates 1 and 4 based on the formal definition of AIDS is an

Then put your money where your mouth is - infect yourself willingly with HIV and don't take any treatments for it.

Surely if it's harmless as cretins like Hogan say, then there's no reason for you not to do it and thus prove to the world that the HIV/AIDS connection is completely false. You would certainly win fame, prestige, riches beyond your wildest dreams for exposing it, right?

There is some humor I could do without. This doesn't even rank as that. This was plain distateful (hence the flamebait rating you received). Obviously not funny to most here. Checking the score it appears that no one found it funny. Perhaps you should evaluate your career choices in comedy.